In particular patients with acute illness that have been admitted to hospital, patients that have been operated on (major surgery in particular), elderly patients and patients with multiple pre-existing diseases have high risk to have Serious Adverse Events (SAE) such as hospital infections, respiratory function disturbance, circulatory disturbance and ultimately cardiac arrest during their hospital stay. For example the prevalence for the risk of imminent cardiac arrest is approximately 5% in hospitalized bedbound patients admitted to acute care departments. Patients that have been discharged from intensive care units (ICUs) without treatment limitations have also an increased risk of SAE resulting in medical emergency team review, readmission to ICU or even death. In spite of the initial recovery from the critical illness, nearly 10% of discharged ICU patients die on general wards and approximately 7 to 10% are acutely readmitted to ICU. Currently the observation and reaction to vital function disturbances rely on high cost human resource available in regular wards. Today there are increasing attempts to optimize production, effectiveness and efficacy in the health care. Attempts to reduce costs and increase the production rely by and large on reducing the number of staff in the wards. At the same time population ages and patients have at the time of hospital admission higher number of chronic pre-existing illnesses. The afore mentioned scenario with the attempts to increase production evolves to untoward risk field with unacceptably high rate of in-hospital cardiac arrests in worst case and prolonged hospitalization with long lasting human suffering and further costs to the society and individuals and families.
There are multiple risk factors which are associated with increased morbidity and mortality among hospitalized patients in general and in post-ICU patients in particular. These factors are related to hospital/ICU admission type, patient characteristics and several variables related to the disease, the patient and the treatment. At the same time, recent studies regarding medical emergency teams (MET) and prevalence of MET activation criteria in general wards imply that the ward level care in hospitals is often suboptimal. Basic vital functions (or dysfunctions) are not recorded or treated as would be expected. If this is applied to post-ICU patients too, recovery from critical illness may be compromised even after successful intensive care and discharge from ICU.
Results from previous studies show that prevalence of abnormal vital signs, recognized as positive MET criteria, was worryingly high among patients discharged from intensive care. Altered vitals were not regarded as early signs of deterioration requiring intervention, when presented to ward staff, even though MET has been active in hospital since 2009. After the first 24 h in general ward, recorded vital deviations (measured heart rate, systolic blood pressure, peripheral arteriolar oxygen saturation and respiratory rate) and attending nurse's concern about patient were the only factors independently associated with SAEs among discharged ICU patients. As a conclusion, simple vital function measurement and attending ward nurse's subjective assessment facilitate early detection of post-ICU patients at risk.
For early risk recognition few vital biosignals are typically monitored, such as blood pressure, heart rate, blood oxygen saturation and respiratory rate. According to conventional case the blood pressure is measured by a pressure cuff, which heavily interferes with or even blocks the blood circulation. Thus it interferes e.g. with other measurements, such as measurement of blood oxygen saturation at fingertip. In addition many of the known systems have plurality of sensors with lots of wires located around the body of the patient, which makes the systems inconvenient, as well as also unhygienic.